species particularly at risk bc of low or declining numbers or small range,but not a threatened species.

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what is a threatened species

whose population is not low enough to be in immediate danger of extinction,who certainly faces serious problems.Could become endangered if problems rant resolved.the red kangaroo

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what is an endangered species

in immediate danger of becoming extinct,its numbers are usually low and it needs protection in order to survive. e.g. the snow leopard

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what is an extinct species

one that is no longer living. e.g. the stegosaurus.

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what does CITES do?

the convention on international agreement between governments. Its aim is to ensure that international trade in specimens of wild animals and plants does not threaten their survival.

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what is an ecosystem?

an environment consisting of all the organisms(bacteria plants trees insects etc) and non living components (air,water,sand,sunlight etc) in a particular area.The more species there are in a area,the more stable the ecosystem.

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describe the size of ecosystems

range from the ecosystem of a single rock pool to a entire ocean, or even an entire planet. an ecosystem provides all the habitat nutrients food and water for all organisms survival.

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how is biodiversity measured?

used as a way to measure the health of an ecosystem. greater biodiversity-greater health!

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name the 3 different types of diversity

species diversity, genetic diversity and ecosystem diversity.

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explain species diversity.

important there is diversity in form of abundant species and should be enough of a certain type of species that predators can feed without devising the population of their prey. important ecosystem is species 'rich' so community can have food supply.

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explain genetic diversity.

important in order to adapt to environmental change.To survive a species needs to defend themselves against attack accessfood water and find a habitat.Need to adapt against predators and disease.

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the biggest threat to conservation is human activity. name some examples

deforestation,coastal development,pollution,road building

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name some benefits of biodiversity

provides potential foods,industrial materials and new medicines for human wellbeing. Stable ecosystems help to regulate the atmosphere water supply and nutrient cycles and provide fertile soil.

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what are the reasons for a reduction in species numbers?

changes in land use:e.g. building. Climate change:some species can no longer survive in given area. Over exploitation-over-fishing threatens populations.Introduction of alien species-can push out existing species.

look closely at a smaller area and calculating the numbers in the large area mathematically. same area must be typical of the whole area.

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how do scientists use quadrats while measuring biodiversity

placed randomly in the area to be studied.individuals of different species in each quadrat then counted and recorded. important placed randomly so not biased.-can be done by using a random number generator to decide which grid squares to place on.

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how do scientists use transects while measuring biodiversity

samples taken at every metre and species under the sampling point are recorded.